drivers/network/ndisuio/misc.c

   1 /*
   2  * COPYRIGHT:   See COPYING in the top level directory
   3  * PROJECT:     ReactOS NDIS User I/O driver
   4  * FILE:        misc.c
   5  * PURPOSE:     Helper functions
   6  * PROGRAMMERS: Cameron Gutman (cameron.gutman@reactos.org)
   7  */
   8
   9 #include "ndisuio.h"
  10
  11 #define NDEBUG
  12 #include <debug.h>
  13
  14 NDIS_STATUS
  15 AllocateAndChainBuffer(PNDIS_PACKET Packet, PVOID Buffer, ULONG BufferSize, BOOLEAN Front)
  16 {
  17     NDIS_STATUS Status;
  18     PNDIS_BUFFER NdisBuffer;
  19
  20     /* Allocate the NDIS buffer mapping the pool */
  21     NdisAllocateBuffer(&Status,
  22                        &NdisBuffer,
  23                        GlobalBufferPoolHandle,
  24                        Buffer,
  25                        BufferSize);
  26     if (Status != NDIS_STATUS_SUCCESS)
  27     {
  28         DPRINT1("No free buffer descriptors\n");
  29         return Status;
  30     }
  31
  32     if (Front)
  33     {
  34         /* Chain the buffer to front */
  35         NdisChainBufferAtFront(Packet, NdisBuffer);
  36     }
  37     else
  38     {
  39         /* Chain the buffer to back */
  40         NdisChainBufferAtBack(Packet, NdisBuffer);
  41     }
  42
  43     /* Return success */
  44     return NDIS_STATUS_SUCCESS;
  45 }
  46
  47 PNDIS_PACKET
  48 CreatePacketFromPoolBuffer(PVOID Buffer, ULONG BufferSize)
  49 {
  50     PNDIS_PACKET Packet;
  51     NDIS_STATUS Status;
  52
  53     /* Allocate a packet descriptor */
  54     NdisAllocatePacket(&Status,
  55                        &Packet,
  56                        GlobalPacketPoolHandle);
  57     if (Status != NDIS_STATUS_SUCCESS)
  58     {
  59         DPRINT1("No free packet descriptors\n");
  60         return NULL;
  61     }
  62
  63     /* Use the helper to chain the buffer */
  64     Status = AllocateAndChainBuffer(Packet, Buffer, BufferSize, TRUE);
  65     if (Status != NDIS_STATUS_SUCCESS)
  66     {
  67         NdisFreePacket(Packet);
  68         return NULL;
  69     }
  70
  71     /* Return the packet */
  72     return Packet;
  73 }
  74
  75 VOID
  76 CleanupAndFreePacket(PNDIS_PACKET Packet, BOOLEAN FreePool)
  77 {
  78     PNDIS_BUFFER Buffer;
  79     PVOID Data;
  80     ULONG Length;
  81
  82     /* Free each buffer and its backing pool memory */
  83     while (TRUE)
  84     {
  85         /* Unchain each buffer */
  86         NdisUnchainBufferAtFront(Packet, &Buffer);
  87         if (!Buffer)
  88             break;
  89
  90         /* Get the backing memory */
  91         NdisQueryBuffer(Buffer, &Data, &Length);
  92
  93         /* Free the buffer */
  94         NdisFreeBuffer(Buffer);
  95
  96         if (FreePool)
  97         {
  98             /* Free the backing memory */
  99             ExFreePool(Data);
 100         }
 101     }
 102
 103     /* Free the packet descriptor */
 104     NdisFreePacket(Packet);
 105 }
 106
 107 PNDISUIO_ADAPTER_CONTEXT
 108 FindAdapterContextByName(PNDIS_STRING DeviceName)
 109 {
 110     KIRQL OldIrql;
 111     PLIST_ENTRY CurrentEntry;
 112     PNDISUIO_ADAPTER_CONTEXT AdapterContext;
 113
 114     KeAcquireSpinLock(&GlobalAdapterListLock, &OldIrql);
 115     CurrentEntry = GlobalAdapterList.Flink;
 116     while (CurrentEntry != &GlobalAdapterList)
 117     {
 118         AdapterContext = CONTAINING_RECORD(CurrentEntry, NDISUIO_ADAPTER_CONTEXT, ListEntry);
 119
 120         /* Check if the device name matches */
 121         if (RtlEqualUnicodeString(&AdapterContext->DeviceName, DeviceName, TRUE))
 122         {
 123             KeReleaseSpinLock(&GlobalAdapterListLock, OldIrql);
 124             return AdapterContext;
 125         }
 126
 127         CurrentEntry = CurrentEntry->Flink;
 128     }
 129     KeReleaseSpinLock(&GlobalAdapterListLock, OldIrql);
 130
 131     return NULL;
 132 }
 133
 134 VOID
 135 ReferenceAdapterContext(PNDISUIO_ADAPTER_CONTEXT AdapterContext)
 136 {
 137     /* Increment the open count */
 138     AdapterContext->OpenCount++;
 139 }
 140
 141 VOID
 142 DereferenceAdapterContextWithOpenEntry(PNDISUIO_ADAPTER_CONTEXT AdapterContext,
 143                                        PNDISUIO_OPEN_ENTRY OpenEntry)
 144 {
 145     KIRQL OldIrql;
 146
 147     /* Lock the adapter context */
 148     KeAcquireSpinLock(&AdapterContext->Spinlock, &OldIrql);
 149
 150     /* Decrement the open count */
 151     AdapterContext->OpenCount--;
 152
 153     /* Cleanup the open entry if we were given one */
 154     if (OpenEntry != NULL)
 155     {
 156         /* Remove the open entry */
 157         RemoveEntryList(&OpenEntry->ListEntry);
 158
 159         /* Invalidate the FO */
 160         OpenEntry->FileObject->FsContext = NULL;
 161         OpenEntry->FileObject->FsContext2 = NULL;
 162
 163         /* Free the open entry */
 164         ExFreePool(OpenEntry);
 165     }
 166
 167     /* Release the adapter context lock */
 168     KeReleaseSpinLock(&AdapterContext->Spinlock, OldIrql);
 169 }